The present invention relates generally to thrust bearing assemblies and, more particularly, to a thrust bearing assembly including lubricant flow passages.
A typical thrust bearing assembly includes a pair of races, a bearing retainer or cage positioned between the races and defining a plurality of circumferentially-spaced openings, and one or more rolling elements positioned in at least some of the openings. One type of bearing cage is a Sigma-type cage, in which the bearing cage has a Sigma-shaped configuration, as viewed in longitudinal section. The bearing assembly is generally used between two relatively-moving structures of an apparatus, such as, for example, a torque converter.
Lubricant is typically provided to the bearing assembly to lubricate the components of the bearing assembly. Lubricant may also be provided through the bearing assembly to lubricate the additional structures of the apparatus which are downstream of the bearing assembly.
One independent problem with existing thrust bearing assemblies is that the bearing assemblies restrict the flow of lubricant to the additional downstream structures in the apparatus. The bearing assembly is a xe2x80x9cchoke-pointxe2x80x9d of lubricant flow in the apparatus.
The present invention provides a bearing assembly which substantially alleviates one or more of the above-identified and other problems with existing bearing assemblies, The bearing assembly includes a bearing retainer or cage defining one or more lubricant flow passages which improve the flow of lubricant to the components of the bearing assembly and through the bearing assembly. In one aspect, the cage defines a lubricant outlet which is axially aligned with the radially-outer, downstream annular gap defined by the races. In another aspect, the cage defines a passage having a lubricant inlet axially aligned with the radially-inner, upstream annular gap defined by the races, a lubricant outlet which is axially aligned with the radially-outer, downstream annular gap defined by the races, and an internal radial passage radially aligned with and communicating between the inlet and the outlet.
More particularly, the invention provides a bearing assembly including a first race having an axially extending section and a radially extending section, a second race having an axially extending section and a radially extending section, the axially extending section of the first race being substantially plane parallel with the axially extending section of the second race, the radially extending section of the first race being substantially plane parallel with the radially extending section of the second race, the radially extending section of the first race and the axially extending section of the second race defining a first annular gap, the radially extending section of the second race and the axially extending section of the first race defining a second annular gap, a cage supported between the first race and the second race, the cage having a body defining a plurality of circumferentially spaced openings, the body defining an inlet passage and an outlet passage in fluid communication with the inlet passage, the outlet passage extending axially through the cage body and being axially aligned with the second annular gap, and a plurality of rolling elements, ones of the plurality of rolling elements being positioned within a selected ones of the plurality of openings.
Preferably, the inlet passage is in fluid communication with at least one of the plurality of openings, and the outlet passage is in fluid communication with at least one of the openings. In some constructions, the body is preferably of a Sigma-shaped configuration, as viewed in longitudinal section.
The body may form a substantially circular channel, the channel in fluid communication with the plurality of openings, the inlet passage, and the outlet passage. Further, the body may form a substantially circular second channel, the second channel in fluid communication with the plurality of openings, the inlet passage, and the outlet passage.
Preferably, the inlet passage is axially aligned with the first annular gap. The body preferably defines an internal radial passage fluidly connecting the inlet passage and the outlet passage, the radial passage being radially aligned with the inlet passage and the outlet passage. Preferably, the radial passage extends radially through the body a first radial distance, the plurality of openings each extend radially through the body a second radial distance, and the first radial distance is greater than the second radial distance. The body may define a plurality of inlet passages, and a plurality of outlet passages each extending axially through the cage body and each axially aligned with the second annular gap.
Also, the present invention provides a bearing assembly including a first race having an axially extending section and a radially extending section, a second race having an axially extending section and a radially extending section, the axially extending section of the first race substantially plane parallel with the axially extending section of the second race, the radially extending section of the first race substantially plane parallel with the radially extending section of the second race, the radially extending section of the first race and the axially extending section of the second race defining a first annular gap, the radially extending section of the second race and the axially extending section of the first race defining a second annular gap, a cage supported between the first race and the second race, the cage having a body defining a plurality of circumferentially spaced openings, the body defining a radial passage having an inlet and an outlet, the inlet being in fluid communication with the first annular gap, the outlet extending axially through the cage body and being axially aligned with the second annular gap, and a plurality of rolling elements, ones of the plurality of rolling elements being positioned within selected ones of the plurality of openings.
In addition, the present invention provides a cage for a bearing assembly, the cage including a body defining a plurality of circumferentially spaced openings, each opening having a first radial length, at least one of the plurality of openings accommodating a rolling element, and a radial passage having an inlet and an outlet, the outlet extending axially through the body, the radial passage having a second radial length, the second radial length being greater than the first radial length.
One independent advantage of the bearing assembly of the present invention is that there is improved lubricant flow through the bearing assembly. The radial lubricant passage allows improved flow through the bearing assembly.